The formula worked beautifully for Phil Mickelson in Thursday’s opening round of the U.S. Open.

Attend his daughter’s eighth-grade graduation ceremony in suburban San Diego. Hop on his private jet for a 41/2 -hour coast-to-coast flight to Philadelphia and arrive at 3:30 a.m. Squeeze out a few hours sleep and another hour during a long rain delay. Finish with the lead in the 113th national championship at Merion Golf Club.

It seemed like an exhausting 18 hours or so for Mickelson, but he was incredibly sharp in firing a 3-under-par 67 for a 2-stroke lead on the players who had finished on a day that featured two suspensions for rain and lightning totaling more than four hours.

Play was halted the first time at 8:36 a.m. and the players did not resume competition until 12:08 p.m. Another stoppage at 6:10 p.m. lasted until 6:55 p.m., and the contestants kept going before darkness halted play for the day at 8:16.

At 4-under par, Luke Donald led players who hadn’t completed their round, reaching that figure with consecutive birdies on holes 11 through 13. Masters champion Adam Scott birdied the 11th hole to get to 3-under.

The 78 players who teed off in the morning all completed 18 holes. The 78 in the afternoon wave played between four and 14 holes and were to resume their rounds at 7:15 a.m. Friday. After they finish, they will go back out to the East Course for the second round.

Playing with Scott and Rory McIlroy in the day’s featured grouping, Tiger Woods bogeyed three of his first five holes and appeared to have tweaked his left wrist at least three times on shots out of the rough. He stood at 2-over-par facing a par putt on the 11th hole when play begins Friday.

Nicolas Colsaerts, grouped in a long-driving trio with Columbia native Dustin Johnson and Bubba Watson, fired a 69, the only other player besides Mickelson to finish 18 holes Thursday below par. Five players, including Rickie Fowler and Charl Schwartzel, completed their round at even par 70.

Thursday’s rain, which totaled more than a half-inch, made the greens soft and slower. Mickelson said the course “played as easy and it’s going to play … soft fairways, soft greens and no mud balls. So we had the opportunity to score low.”

Mickelson had planned to go home for his daughter Amanda’s graduation after a practice round, but when he saw the rain pour down Monday, he decided to leave early even though Amanda told him it was all right if he stayed to prepare. But he didn’t consider it.

“She told me, ‘It’s fine, it’s the U.S. Open, I know how much you care about it,’ ” he said. “I told her I want to be there. I don’t want to miss that. I don’t want to miss her speech. She’s worked very hard and I’m very proud of her.”

He also hit balls while at home. He read his notes about how to play the course on the plane ride east.

“I got all my work done on Merion when I was here a week and a half ago,” he said. “I knew exactly how I wanted to play the golf course, given the conditions, given different wind conditions, clubs I was going to be hitting … So I didn’t feel I needed more time at Merion. I needed to get my game sharp, to get my touch sharp.”

Mickelson admitted he hit the wall with two holes to play, but he managed to birdie one of them, the par-3 ninth, and finish smiling.